Can you meaningfully measure how environmentally friendly a website is?
https://shkspr.mobi/blog/2025/05/can-you-meaningfully-measure-how-environmentally-friendly-a-website-is/
Think global; act local. That's the mantra, right? I can't stop coal plants belching out suffocating pollutants, but can I ensure my website is as environmentally friendly as possible?
There are several services which claim to be able to detect just how lean, green, and clean your website is. But, in my opinion, they're all a bit inadequate.
WebsiteCarbon
The WebsiteCarbon.com service gives me this very pleasing report
But what does that actually mean? There's an almost content-free description of their rating system. It boils down to how large your web pages are and whether your data centre runs on green energy.
I specifically chose Krystal as my host because of their green energy credentials. So it got that right.
WebsiteCarbon seems to just be an advertising pitch for their paid-for auditing services:
You can get a comprehensive view of a website’s emissions and potential improvements by carrying out a Website Carbon Audit.
Let's try another service.
EcoGrader
EcoGrader gives me a lower score but provides a lot more detail about why.
They also give tips on how I can improve things.
Do you notice anything about those tips? They're basically the same as Core Web Vitals! A set of useful, if generic, tips to optimise your website.
Others
There are several other services which claim to measure your site's eco-credentials. But, as far as I can tell, they're all doing the same thing; reskinning Core Web Vitals or similar products.
Some, like, Blacklight are promoted on the claim that excessive tracking scripts are an environmental disaster. In the end, the message is the same - clean up your website to make it faster more efficient.
What Does This Mean?
The energy efficiency of modern codecs is often asymmetric. It might be energy intensive to encode a movie - but that's paid back a thousand-fold by having to store and stream less data and by the efficiency of the decode process at the user's end.
If you operating at planetary scale then, yes, a small saving affecting a billion users will have a huge impact. If you're optimising a single hero image on your recipe blog, probably not so much.
Much like the discredited idea that by switching off your "standby" devices you can save £££, most of these website changes are marginal at best.
Yes, we should strive for svelte and performant websites - as much for usability as for environmentalism. It makes ecological sense to choose a hosting provider who is at least somewhat responsible in their energy usage - as much for cost as for anything else.
If these websites help convince your boss that you can remove horrific amounts of JS, upgrade images to WebP, and set sensible caching policies - great! Sell them the shiny accreditation badge while you go about making the site better.
Finally, a word of caution to anyone implicitly trusting these services - there's no way to know what's going on in the background of a website. An ultra efficient looking website served from a green data-centre, might be spinning up a dozen LLMs just to churn out the page content. A slow website might be solar powered. All those ultra-compressed images might be adverts for fossil fuels.
And every time you leave a comment on my blog, I shoot a panda.
#EnergySaving #EnergyCrisis #environment #green #websites
Terence Eden
Terence Eden’s Blog
Leon Bex
Games People Play